[Qemu-devel] [PATCHv2 11/11] iscsi: assert that sectors are aligned to LUN blocksize

[Peter Lieven]

if the blocksize of an iSCSI LUN is bigger than the BDRV_SECTOR_SIZE
it is possible that sector_num or nb_sectors are not correctly
alligned.

to avoid corruption we fail requests which are misaligned.

Signed-off-by: Peter Lieven <p...@kamp.de>
---
 block/iscsi.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index 0567b46..bff2e1f 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -298,6 +298,13 @@ static int64_t sector_lun2qemu(int64_t sector, IscsiLun 
*iscsilun)
     return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
 }
 
+static int64_t is_request_lun_aligned(int64_t sector_num, int nb_sectors,
+                                      IscsiLun *iscsilun)
+{
+    return ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
+            (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) ? 0 : 1;
+}
+
 static int
 iscsi_aio_writev_acb(IscsiAIOCB *acb)
 {
@@ -382,6 +389,10 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
     IscsiLun *iscsilun = bs->opaque;
     IscsiAIOCB *acb;
 
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        return NULL;
+    }
+
     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
     trace_iscsi_aio_writev(iscsilun->iscsi, sector_num, nb_sectors, opaque, 
acb);
 
@@ -524,6 +535,10 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
     IscsiLun *iscsilun = bs->opaque;
     IscsiAIOCB *acb;
 
+    if (!is_request_lun_aligned(sector_num, 0, iscsilun)) {
+        return NULL;
+    }
+
     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
     trace_iscsi_aio_readv(iscsilun->iscsi, sector_num, nb_sectors, opaque, 
acb);
 
@@ -687,6 +702,10 @@ iscsi_aio_discard(BlockDriverState *bs,
     IscsiLun *iscsilun = bs->opaque;
     IscsiAIOCB *acb;
 
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        return NULL;
+    }
+
     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
 
     acb->iscsilun    = iscsilun;
@@ -878,6 +897,10 @@ static int coroutine_fn 
iscsi_co_is_allocated(BlockDriverState *bs,
     struct IscsiTask iTask;
     int ret;
 
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        goto fail;
+    }
+
     /* LUN does not support logical block provisioning */
     if (iscsilun->lbpme == 0) {
         *pnum = nb_sectors;
@@ -949,6 +972,10 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, 
int64_t sector_num,
     struct IscsiTask iTask;
     struct unmap_list list[1];
 
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        return -EIO;
+    }
+
     if (!iscsilun->lbprz || !iscsilun->lbpu || !(bs->open_flags & 
BDRV_O_UNMAP) ||
         sector_qemu2lun(nb_sectors, iscsilun) > iscsilun->max_unmap) {
         /* fall back to writev */
-- 
1.7.9.5